Metal-working machine.



Patented Apr. 1, 191 9 3 SHEETSSHEET I.

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M M w TTOHIVEY C. L. GOODRICH.

METAL WORKING MACHINE.

APPLICATION FILED SEPT. :4. 1911.

Patented Apr. 1, 1919.

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c. L. GOODRICH. METAL WORKING MACHINE.

APPUCATION FILED SEPT- l4. \9] 1- Patented Apr. 1,1919.

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CLARENCE L. GOODRIGH, or HARTFORD, coNNEorIour, AssIGNOR "ro rRA'r'r & WHITNEY COMPANY, on NEW YORK, N. Y., A CORPORATION on NEW JERSEY.

METAL-WORKING MACHINE.

Specification of Letters Patent.

Patented Apr. i, 1919.

Application filed September 14, 1917. Serial No. 191,342.

To all whom it may concern:

Be it known that I, CLARENCE L. Goon- RICH, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Metal- Working Machines, of which the following is a specification.

A machine embodying the invention may be used with advantage in a variety of different ways, two of the many illustrations being thread-forming and lapping as it is known. The invention is particularly useful in forming a thread, being of such a character as to prevent the chip or chips from choking in the cut or interfering with the proper action of the threading-tool Whether the thread be internal or external. In the case of lapping the function in question can be obtained in a highly effective, accurate and uniform manner.

The machine comprises broadly means for supporting the work and the tool in coiiperative relation with each other in conjunction with means for relatively rotating the work and the tool and in also relatively operating the tool andt-he work to secure a seriesof oscillations or forward and backwardmovements, the forward movement in each step being preferably greater than the backward movement. The backward movement in thread-cutting is utilized to break off a chip, in view of which the possibility of the chips choking in or around the cut is virtually eliminated. Preferably the machine is so constructed that each step of the oscillations gradually increases and decreases in speed.

By preference, for effecting such oscillations, I provide a mechanism which comprises a train of permanently engaging power trans mitting elements which extends from the initial driving device.

In the drawings accompanying and forming part of the present specification I have shown in detail one form of embodiment of a machine involving the invention. y In this particular machine the tool is a tapping tool being intended to cut a thread inside a piece of hollow work, but it will be understood that the tool may be such a one as to form an external thread. As a mat ter of fact the tool may be of any suitable character, and the same statement applies to the work.

Referring to the drawings:

Figure 1 is a side elevation of the upper portion of a machine involving the invention.

Fig. 2 is a sectional side elevation of the headstock portion of the machine.

Fig. 3 is a view of certain operating gearing hereinafter more particularly described and looking toward the left in Fig. 2.

Fig. 4 is a diagram showing certain of the gear members, and illustrating by dotted lines the action of the segment.

Figs. 5 to 8 inclusive are diagrams illustrative of the procedure in tapping.

Fig. 9 is a cross section of the (tap shown in Figs. 5 to 8 inclusive. I

Referring to Fig. 1 the numeral 2' denotes a suitable base or bed upon which the operative parts of the machine may be mounted. As already intimated either the work or the tool or both may be rotated. In the present case only thetool is rotated, the work as 3 being held stationary for example by a chuck as4 on the innerend of the spindle 5 of the tailstock 6 sustained for adjustment on the base or bed 2 after the manner common in lathes and other metal working machines. The headstock 7 sustains the main spindle 8 represented as having fastened to it. a cone pulley 9 adapted to be operated by a suitable belt (not shown) and constituting a suitable driver for said spindle. The spindle S can be considered as constituting the initial driving device of the mechanism to which the invention particularly relates. Preferably, as is usual in lathes, this spindle or driving device rotates continuously in one direction. Between theinitial drivingdevice and the tool there is provided a train of permanently engaging power transmitting elements. When the initial driving device rotates always in the same direction, as herein set forth, the power transmitting elements are so arranged and constructed as to reverse thetool, driving it alternately in opposite directions, the extent of movement in one direction being greater than that in the other direction.

The shank of the tap 10 (constituting a suitable tool) is held in. a chuck 11 at the front end of the auxiliary spindle or stub s inside of the headstock or hearing 7 is a spur gear as 15, which is stationary in the present case and which constitutes a convenient circular rack. As shown said spur gear is concentric with the spindle 8, being fastened to the headstock or bearing 7 by one or more screws 16. Threaded onto the forward end of the spindle .8 is the hub or body of an arm 18,, the latter, therefore, being rotarry or revoluble with the spindle 8. Through the hub of said revolving arm 18 the auxiliary spindle or stub shaft 12 extends. Projecting through the arm 18 at a point removed from its center of revolution 'andnear the end thereof is the shaft 19. At

theouter end said shaft 19 is equipped with the pinion 20 in mesh with the teeth of the fixed spur gear 15, It will be clear, there-.

fore, that if the pulley 9 be rotated, it will turn the spin le 8 and therefore the arm 18,

thus causing t 1e pinion 20 to revolve about the fixed 15, and the consequent rotation of said pinion and the shaft 19. The inner end of the shaft 19 is provided with a crank '21 to which the connecting rod 22 is jointed, at one end, the other end of the connecting rod being similarly connected to the body" of the toothed segment or sector 23 pivoted for oscillation as at 2 f to the branch 25 of the arm or carrier 18. The teeth of the segment or sector 23 mesh with the teeth of the pinion 26 fastened in some desirable manner as by pinning, to the spindie 12.

As the arm 18 is revolved in the manner set forth, it follows that the pinion 20 and shaft 19 will be f gtated as also described, to cause through the crank 31 an oscillation of the, seginentQa and the resultant oscillation of the'pinion 26 and tool 10, the forward part or'advance of each step in the oscillation being greater than the rear or retractive partas illustrated diagrammatically in Figs. 3 and t. The fact that the segment or sector 22; is being moved backward to secure a corresponding motion of the pinion 2 6 and hence of the tool 10 during the forward n10- tion of the arm 8 is in the present case the cause of this decrease in back movement of the tap with respect to the advance movement thereof. It will be apparent that I provide means for giving to the tool a greater forward movement than retractive moveiiient on each oscillation or step of the tool. owing to WhlOll circmnstan'ce the tool whether a tap or some other implement is given complete rotation after a certain number of oscillations, and the number of oscillations and their amplitude forward and back may be adjusted or regulated to suit the necessary conditions. In the case of a tap with four flutes, the advance movement of each oscillation would be more than ninety degrees, while the rear orretractive movement should be sufficient to wholly break or separate each chip from the work or stock. This is illustrated diagrammatically in Figs. 5 to 8 inclusive. 'Each step of oscillation gradually increases and decreases in speed, thus largely avoiding shock and vibration.

It will be assumed that the tap 10 has been introduced into the work 3 and that the pulley 9 is being rotated. As a result the tap is given a series of oscillations or forward and backward movements. In Figs. 5 to 9 inclusive the flutes of the tap are denoted by 80, 31, 32 and 33 respectively, Fig. 5 shows the tap 10 just after it has been introduced into the work 3. On the initial forward movement ofthe first oscillation of the tap, the flutes assume the position shown in Fig, 6 with the gearing proportionated as shown. In said Fig. 6'1 have shown the cutting edges of the four flutes as having cut chips. At the conclusion of the advance movement of the first oscillation the tap is reversely moved to the position shown for instance in Fig. 7 and on this particular Inotion the flutes break off the chips as illustrated inFig 7 at which pointthe tap is given the advance part of its second oscillation which it is shown as having completed in Fig. 8. On the backward movement of the second oscillation the flutes forward of the chi 3s break off the previously formed chips back of them. These motions are con tinued until the work is threaded. The threaded hole will be clean, free of protru- 105 sions, and there is no possibility of the chips interfering with the free, proper rotation and cutting action of the tool.

In order to withdraw the tap from the threaded hole the mechanism which I have 110 described may be operated in the reverse direction and the oscillating movement during withdrawal may, under some circumstances, be advantageous. It will be understood, however, that it is not necessary to withdraw 115 the tap in this way and that it may be withdrawn by unscrewing in the usual manner. This unscrewing may be effected eitherby releasing the work and turning it relatively to the tap, or by releasing the tap from the 120 chuck 11 and turning it by hand, or by efiecting relative turning in any other way.

It will be obvious to those skilled in the art that the invention is not limited to any particular means for supporting and hold- 12s ingthe tapping device and the work. As shown, thedevice is mounted in a lathe with the axis of the tap and of the hole to be tapped positioned horizontally, but it will be clear that the device may be mounted in 130 a tool of a difierent type, such as a drill press, and that the axis may beotherwise positioned, as, for instance, vertically. It is merely necessary for the taping device and for the work to be so positioned relatively that the axis of the tap is in alinement with the axis of the hole to be tapped and that relative longitudinal movement be permitted to enable the tap to enter the hole. In the present case the work is movablelongitudinally to. follow the threads of the tap, but obviously the work might beheld fixed and the tap permitted to move longitudinally.

What I claim is: i A

1. Ina machine of the class described, the combination with workholding means and means forholding a tool in position to act 011 the work,'of an initial driving devicefand means comprising a train of permanently engaging power transmittin elements associated with the driving device for imparting relatively to the tool and the work a succession of steps of forward and backward movements and for securing a greater degree of movement during one part of each step than during the other.

2. In a machine of the class described, the combination with Work holding means and means for holding a screw-threadin tool in position to act on the work, of an initial driving device, and means comprising a train of permanently engaging power transmitting elements associated with the driving device for imparting relatively to the tool and the work a. succession of oscillations and for se-- curing a greater degree of forward movement than backward movement on each oscillation.

3. In a machine of the class described, the combination with work holding means and means for holding a tap in position to act on the work, of an initial driving device, and means comprising a train of permanently engaging power transmitting elements associated with the driving device for imparting to the tap a succession of oscillations and for securing a greater degree of forward movement than backward movement on each oscillation of the tap.

4. In a machine of the class described, the combination with work holding means and means for holding a tool in position to act on the work, of an initial driving device continuously rotating in one direction, and means comprising a train of permanently engaging power transmitting elements associated with the driving device for imparting relatively to the tool and the work a succession of steps of forward and backward movements and for securing a greater degree of movement during one part of each step than durin the othe 1 5. n a machine of the class described, the combination with Work holding means and means for holding a tool in position to act 'on the work, of means for imparting to the tool a succession of oscillations having steps each gradually increasing and decreasing in speed and for securing a greater, degree of movement in one direction than in the other on each oscillation.

6. In a machine of the class described,the combination with work holding means and means for holding a tool in position to act on the work, of an initial driving device continuously rotating in one direction, and means associated with the driving device for imparting relatively to the tool and the work a succession of oscillations having steps each gradually increasing and decreasing in speed and forsecuring a greater degree of movement in one direction than in the other on each oscillation.

7. In a machine of the class described, the combination with work holding means and means for holding a tap in position to act on the work, of an initial driving device continuously rotating in one direction, and( means associated with the driving device for imparting relatively to the tap and the work a succession of oscillations having steps each gradually increasing and decreasing in speed and for securing a greater degree of forward movement than backward movement on each oscillation.

8. In a machine of the class described, the combination with work holding means and means for holding a tool in position to act on the work, of an initial driving device continuously rotating in one direction, and means associated with the driving device for imparting to the tool a succession of oscillations having steps each gradually increasing and decreasing in speed and for securing a greater degree of movement in one direction than in the other on each oscillation.

9. In a machine of the class described, the combination with work holding means and means for holding a tool in position to act on the work, of an initial driving device, and bodily rotatable means associated with the driving device for, imparting to the tool a succession of oscillations and for securing a greater degree of forward movement than backward movement on each oscillation of the tool.

10. In a machine of the class described, the combination of a tool spindle and a work holding means in cooperative relation, a pinion fixed to the tool spindle, a gear in mesh with the pinion, and means for revolving the gear about the pinion and for also imparting to the gear a succession of oscillations during its revolution about the pinion.

11. In a machine of the class described, the combination of a tool spindle and a work holding means in cooperative relation, an

arm revoluble with respect to the spindle, a stationary spur gear, a shaft supported for rotation by the arm and provided with a pinion in mesh with the spur gear and also provided with a crank portion, and a connecting link between the crank and the spindle.

12. In a machine of the class described, the combination of a tool spindle and a work holding means in cooperative relation, an arm revoluble with respect to the spindle, a pinion rotative with the spindle, a stationary spur gear, a shaft supported for rotation by the arm and provided with a pinion in mesh with the spur gear and also provided with a crank portion, a sector supported for oscillation by the arm and having teeth whichare in mesh with the teeth of the first mentioned pinion, and a Connecting link between the crank and the sector.

13. A tapping attachment for a lathe coinprisin a tap holder adapted to bemounted coaxia ly with the lathe spindle and to be rotated independentlythereof, a driving de vice adapted to be secured'to the lathe spindle, and power transmitting elements interposed between the driving device and the tap holder for imparting progressive oscillatory movements to the holder when the driving device is continuously rotated.

In testimony whereof, I hereto afiix my signature. v

CLARENCE L. GOODRIOH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D, G. 

